Prime Minister Suga Yoshihide will attend a series of Asian online meetings later this week including a summit with the Association of Southeast Asian Nations.
The meetings are scheduled from Thursday until Sunday.
Japanese Prime Minister Abe Shinzo plans to attend the ceremonies to mark the 75th anniversary of the US atomic bombings of Hiroshima and Nagasaki.
Abe told government and ruling coalition executives on Monday that he will participate in the ceremonies in Hiroshima on Thursday and in Nagasaki on Sunday.
NHK has learned that UN Secretary-General Antonio Guterres has given up on his plan to attend a ceremony in Hiroshima City, western Japan, to mark the 1945 US atomic bombing of the city.
Sources say the decision is due to the coronavirus pandemic. Japan has banned entry by foreign nationals from the United States. Even if the UN chief were allowed to enter Japan, he would be asked to self-isolate for 14 days after arriving.